Big draw turns into a weak fold?

[Zapper]

I'm fairly new to the table therefore I don't have any big reads on my opponents.

Party Poker (6 max, 6 handed) converter

Preflop: Hero is SB with 6[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">2 folds</font>,CO calls, BB checks.

Just to make sure, standard complete yes?

Flop: K[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/diamond.gif[/img], 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
Hero bets, BB calls, CO calls

BINGO! Big draw, but alot of people ahead of me. I decide that I should pump the pot with my draw. However, I didn't produce alot of action.

Turn: K[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, BB Bets, CO raises.

Couldn't pick a worse turn card..
I don't want to bet out since I know a king will raise me so I decide to just check call. Now when it's two back to me it's an easy fold correct?

Final Pot:

P.S. The convertor isn't working properly so I had to edit most of the information myself.